Axle assembly for low chassis vehicle

Abstract

Axle assemblies for low chassis vehicles are described herein. The axle assembly includes an axle housing and a drive unit for driving the wheel assembly. The axle housing includes a first gearbox, a second gearbox, and a bracket assembly coupling the first gearbox to the second gearbox. The axle assembly includes a first hub assembly and a second hub assembly forming a first axis of rotation. The first gearbox includes an electric motor coupled to a transmission for rotating the output shaft. The first gearbox also includes a differential mounted for rotation with the transmission and a first reduction box mounted for rotation with the differential. The axle assembly also includes a portal axle mounted to rotate with the first reduction box and extending from the first gearbox to the second gearbox, where the portal axle forms a second axis of rotation that is offset relative to the first axis of rotation of the hub assembly. The second gearbox includes a second reduction box mounted for rotation with the portal axle and adapted to drive the second hub assembly.

Description

[0001] This application is a divisional application of the invention patent application filed on November 24, 2020 with the invention name “Axle assembly for low-floor vehicles” and application number “201980034992.0”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 669,743, filed May 10, 2018. The disclosures set forth in the above-referenced applications are incorporated herein by reference in their entirety. Background Art

[0004] To aid ingress and egress, it is desirable for a motor vehicle to have a chassis that is as low to the ground as possible. Buses and people carriers, often referred to as low-floor vehicles, are examples of vehicles that benefit from a low ride height. By minimizing the ride height, steps on the vehicle doors can be eliminated, which in turn allows vehicle occupants to enter and exit more easily. The elimination of steps is particularly beneficial to disabled passengers, as well as passengers carrying items, such as strollers. To improve performance and efficiency, manufacturers are increasingly turning to electric and hybrid propulsion systems for low-floor vehicles. In order to keep the vehicle's chassis as low as possible, the drive train components are rearranged to reduce intrusion into the vehicle's chassis. Summary of the invention

[0005] Thus, the present disclosure provides an axle assembly for a low floor vehicle having improved performance and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Advantages of the present disclosure will become readily appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings, as the advantages of the present disclosure will become better understood.

[0007] Figure 1 is a perspective view of an axle assembly for a low floor vehicle;

[0008] Figure 2 is a front view of an axle assembly for a low floor vehicle;

[0009] Figure 3 is a cutaway perspective view of a drive unit of an axle assembly for a low floor vehicle;

[0010] Figure 4A It shows the first reduction ratio. Figure 3 A cross-sectional view of a drive unit;

[0011] Figure 4B It shows the second reduction ratio. Figure 3 A cross-sectional view of a drive unit;

[0012] Figure 5-8 According to the embodiment of the present disclosure Figure 1 A perspective view of an axle assembly for a low floor vehicle is shown;

[0013] Fig. 9 yes Figure 5-8 a front elevational view of the rear portion of the axle assembly shown;

[0014] Fig.10 yes Figure 5-8 a front elevational view of the left side of the axle assembly shown;

[0015] Fig.11 yes Figure 5-8 a front elevational view of the right side of the axle assembly shown;

[0016] Fig.12 yes Figure 5-8 A top view of the axle assembly is shown;

[0017] Fig.13 yes Figure 5-8 a bottom view of the axle assembly shown;

[0018] Fig.14 and Fig.15 yes Figure 5-8 A perspective view of the axle assembly shown;

[0019] Fig.16 yes Fig.15 A top view of the axle assembly is shown;

[0020] Fig.17 yes Fig.15 a front elevational view of the rear portion of the axle assembly shown;

[0021] Fig.18 yes Fig.15 a front elevational view of the left side of the axle assembly shown;

[0022] Fig.19 and Fig. 20 According to an embodiment of the present disclosure, it can be used Figure 5-8 A perspective view of a bracket assembly of the axle assembly shown;

[0023] Fig.21 and Fig. 22 yes Fig.19 and Fig. 20 a perspective view of a portion of the carriage assembly shown;

[0024] Fig.23 yes Fig.21 a front elevational view of the front portion of the carriage assembly shown;

[0025] Fig.24 yes Fig.21 a front elevational view of the right side of the carriage assembly shown;

[0026] Fig.25 yes Fig.21 A top view of the bracket assembly is shown;

[0027] Fig.26 yes Fig.21 a bottom view of the carriage assembly shown;

[0028] Fig. 27 It is available for Fig.19 and Fig. 20 a perspective view of a top cover of the carriage assembly shown;

[0029] Fig.28 yes Fig. 27 a view of the top surface of the top cover shown;

[0030] Fig.29 yes Fig. 27 a side view of the top cover shown;

[0031] Fig.30 yes Fig. 27 a view of the bottom surface of the top cover shown;

[0032] Fig.31 It is available for Fig.19 and Fig. 20 a perspective view of the bottom cover of the bracket assembly shown;

[0033] Fig.32 yes Fig.31 a view of the top surface of the bottom cover shown;

[0034] Fig.33 yes Fig.31 a side view of the bottom cover shown;

[0035] Fig.34 yes Fig.31 a view of the bottom surface of the bottom cover shown;

[0036] Fig.35 and Fig.36 According to an embodiment of the present disclosure, it can be used Figure 5-8 A perspective view of a gearbox of the axle assembly shown;

[0037] Fig.37 It is available for Fig.35 and Fig.36 A perspective view of a gearbox housing of the gearbox shown;

[0038] Fig.38 yes Fig.37 A front view of a front portion of a gearbox housing is shown;

[0039] Fig.39 yes Fig.37A front view of a rear portion of the gearbox housing is shown;

[0040] Fig.40 yes Fig.37 A top view of the gearbox housing is shown;

[0041] Fig.41 yes Fig.37 A bottom view of the gearbox housing is shown;

[0042] Fig.42 and Fig.43 yes Fig.37 A side view of the gearbox housing is shown;

[0043] Fig.44 It is available for Fig.35 and Fig.36 A perspective view of a gearbox cover of the gearbox shown;

[0044] Fig.45 yes Fig.44 A top view of the gearbox cover is shown;

[0045] Fig.46 yes Fig.44 A side view of the gear case cover is shown;

[0046] Fig.47 yes Fig.44 A bottom view of the gear case cover is shown;

[0047] Fig.48 is another cutaway perspective view of a drive unit of an axle assembly for a low floor vehicle;

[0048] Figure 49-52 According to the embodiment of the present disclosure Fig.48 A cross-sectional view of the drive unit shown;

[0049] Fig.53 yes Fig.48 A cutaway perspective view of the drive unit shown;

[0050] Fig.54 yes Fig.53 A cross-sectional view of a drive unit;

[0051] Fig.55 yes Figure 5-8 A block diagram of the axle assembly shown;

[0052] Fig.56 According to the embodiment of the present disclosure Figure 1 Another perspective view of the axle assembly for a low floor vehicle is shown;

[0053] Fig.57 yes Fig.56 A top view of the axle assembly is shown;

[0054] Fig.58 yes Fig.56 a bottom view of the axle assembly shown;

[0055] Fig.59 yes Fig.56 A front view of the axle assembly is shown;

[0056] Fig.60 yes Fig.56 a rear view of the axle assembly shown;

[0057] Fig.61 yes Fig.56 a right side view of the axle assembly shown;

[0058] Fig.62 yes Fig.56 a left side view of the axle assembly shown;

[0059] Fig.63 yes Fig.56 a perspective view of the bracket assembly shown;

[0060] Fig.64 yes Fig.63 A top view of the bracket assembly is shown;

[0061] Fig.65 yes Fig.63 Another top view of the bracket assembly shown;

[0062] Fig.66 yes Fig.63 a bottom view of the carriage assembly shown;

[0063] Fig.67 yes Fig.63 A front view of the carriage assembly is shown;

[0064] Fig.68 yes Fig.63 a rear view of the carriage assembly shown;

[0065] Fig.69 and Fig.70 yes Fig.63 a side view of the carriage assembly shown;

[0066] Fig.71 yes Fig.56 A perspective view of the gearbox assembly shown;

[0067] Fig.72 yes Fig.56 A front view of the gearbox housing is shown;

[0068] Fig.73 yes Fig.56 A rear view of the gearbox housing is shown;

[0069] Fig.74 yes Fig.56 A top view of the gearbox housing is shown;

[0070] Fig.75 yes Fig.56 A bottom view of the gearbox housing is shown;

[0071] Fig.76 and Fig.77 yes Fig.56 A side view of the gearbox housing is shown;

[0072] Fig.78 yes Fig.56 Another perspective view of the gearbox assembly shown;

[0073] Fig.79 is a front view of an axle assembly for a low-floor vehicle according to another embodiment of the present disclosure;

[0074] Figures 80-83 According to the embodiment of the present disclosure Fig.79 a schematic diagram of an axle assembly; and

[0075] Figures 84-94 is a perspective view of a wheel drive unit including an electric motor, a transmission and a wheel hub assembly. DETAILED DESCRIPTION

[0076] Referring to the drawings, wherein like reference numerals refer to like parts throughout the several views, Figure 1 and Figure 2 1 shows an axle assembly 10 for a low-floor vehicle. The axle assembly 10 includes an axle housing 12 having a bridging section 14 and an outer section 16 disposed at opposite ends of the bridging section 14. Each outer section 16 is spaced apart from each other in the transverse direction relative to the vehicle. The axle assembly 10 also includes a base 18 coupled to the axle housing 12, which can be used to attach the axle assembly 10 to the vehicle. In addition, a suspension (suspension) control arm 20 can be coupled to the base 18 to movably attach the axle assembly 10 to the vehicle. The vehicle can be an electric vehicle or a hybrid vehicle having an electric motor and an internal combustion generator / engine. Advantageously, the base 18 can be configured to allow the axle assembly 10 to be retrofitted into an existing vehicle. For example, a low-floor bus originally equipped with a conventional axle assembly can be upgraded to include the axle assembly 10 in place of the conventional axle assembly.

[0077] Wheels 22 are coupled to each end of the axle assembly 10 to support the vehicle and transmit power to the road surface, such as Figure 1 and Figure 2In the illustrated embodiment, the axle assembly 10 is of dual wheel construction, wherein a pair of wheels 22 are coupled to each end of the axle assembly 10. Each wheel 22 defines an axis of rotation 24. The axis of rotation 24 of each wheel 22 is generally aligned.

[0078] The axle assembly 10 further includes a wheel drive unit 26 housed within each outer section 16 of the axle housing 12. Figure 3 , 4a and 4b. Each wheel drive unit 26 is configured to operate independently of the other drive unit 26 so that the wheels on the opposite side of the axle can rotate independently of the other side. Each wheel drive unit 26 can operate at a different speed during a turning operation of the vehicle or in response to the available traction at each wheel 22. Each wheel drive unit 26 includes an electric motor 28, a transmission 30 and a hub assembly 32 for mounting one or more wheels 22. The axle housing 12 compactly integrates the electric motor 28 and the transmission 30, improves cooling performance for heat dissipation, and supports the vehicle load through the suspension control arm 20 and the base 18. The transmission 30 allows the vehicle to have an increased top speed while operating more efficiently at low speeds.

[0079] like Figure 2 As shown, the bridging section 14 is arranged between each outer section 16 of the axle housing 12. It is desired that the height of the low chassis is as low as possible and the width is as wide as possible in order to maximize the capacity of the vehicle. Therefore, the bridging section 14 is offset from the rotation axis 24 of the wheel 22 in order to reduce the height of the low chassis of the vehicle. The outer section 16 is configured to accommodate the wheel drive unit 26 in the axle housing. Each outer section 16 has a reduced width in order to increase the width of the low chassis of the vehicle. The bridging section 14 can be formed integrally with the outer section 16, or can be coupled to the outer section 16 using methods commonly used in the art. For example, the bridging section 14 can be welded, crimped or bolted to the outer section 16. The bridging section 14 can be hollow or solid.

[0080] The axle assembly 10 may also include a brake system for the vehicle. The brake system may include a cylinder, a brake hose, a brake drum, a brake rotor 35, a brake caliper 37, etc. In the illustrated embodiment, the brake rotor 35 and the brake caliper 37 are adjacent to the wheel hub assembly 32.

[0081] Reference now Figure 3-4B and Figure 48-54, in which the wheel drive unit 26 is shown and the axle housing 12 has been removed. The drive unit 26 includes an axle shaft 36 coupled to a transmission 30 and a wheel hub assembly 32. The transmission 30 is coupled to both the electric motor 28 and the axle shaft 36, and the wheel hub assembly 32 is coupled to the wheel 22. Therefore, the torque generated by the electric motor 28 is transmitted through the transmission 30 to the wheel hub assembly 32 and then to the wheel 22. The drive unit 26 also includes an elongated axle support 38 coupled to the axle housing 12. The axle shaft 36 is disposed in the axle support 38 between the wheel hub assembly 32 and the transmission 30. As will be discussed in further detail below, the transmission 30 has two reduction ratios that can be selectively engaged by an operator of the vehicle or by using a transmission controller.

[0082] The electric motor 28 generates torque to drive the wheels 22, as shown in Figures 4a, 4b and 48. The electric motor 28 includes a motor shaft 40 protruding from the electric motor 28. A drive gear 42 is fixed to the motor shaft 40. The motor shaft 40 defines a rotation axis 44 extending through the electric motor 28. The electric motor 28 can be a brushed or brushless DC or AC motor, or other types of motors known in the art. The electric motor 28 is oriented so that the motor shaft 40 protrudes in a direction away from the corresponding wheel 22, wherein the rotation axis 44 of the motor shaft 40 is arranged parallel to the rotation axis 24 of the wheel 22. Relative to the vehicle, the electric motor 28 is longitudinally spaced from the rotation axis 24 of the wheel 22.

[0083] By orienting the electric motor 28 so that the motor shaft 40 protrudes in a direction away from the corresponding wheel 22 and is longitudinally spaced from its rotation axis 24, packaging space within the outer section 16 of the axle housing 12 is saved without increasing the width of the outer section 16, as shown in Figures 4a and 4b. The additional packaging space within the outer section 16 allows the transmission 30 to be arranged adjacent to the electric motor 28. Preferably, the overall width of the electric motor 28 is substantially similar to the overall width of the transmission 30. Therefore, the width of the outer section 16 is substantially unaffected by the introduction of the electric motor 28. In other words, when the transmission 30 is arranged adjacent to the electric motor 28, the width of the low chassis can be wider than when the transmission 30 is arranged in another manner. In addition, the increased packaging space within the outer section 16 allows the transmission 30 to be configured with multiple reduction ratios. Arranging each rotation axis 24, 44 in a parallel manner improves the efficiency of the transmission 30.

[0084] As described above, the drive unit 26 includes the transmission 30, as shown in FIGS. 4a, 4b and 54. The transmission 30 has a first reduction ratio and a second reduction ratio. The transmission 30 includes an input idler shaft 46, an output shaft 48 and a shift mechanism 50. Both ends of the idler shaft 46 and the output shaft 48 are rotatably supported by bearings 52 in the drive unit 26. The driven gear 54 is fixed to the idler shaft 46 and meshes with the drive gear 42. The driven gear 54 transfers torque from the drive gear 42 to the idler shaft 46.

[0085] In addition to the driven gear 54, two idler gears 56, 58 are also rotatably supported on the idler shaft 46. The first idler gear 56 corresponds to the first reduction ratio of the transmission 30, and the second idler gear 58 corresponds to the second reduction ratio of the transmission 30. Each idler gear 56, 58 is freely rotatable on the idler shaft 46 so that when the corresponding reduction ratio is not engaged, no torque is transmitted between the idler shaft 46 and the idler gears 56, 58. As will be discussed in further detail below, each idler gear 56, 58 includes a spline portion that can engage with the shift mechanism 50 to non-rotatably (rotationally) couple the idler gear 56, 58 to the idler shaft 46.

[0086] The shift mechanism 50 of the transmission 30 includes a shift ring 60, a shift fork (not shown), and an actuator (not shown). The shift ring 60 can slide between the first idler gear 56 and the second idler gear 58 along the idler shaft 46. The shift ring 60 is non-rotatably coupled to the idler shaft 46 so that the shift ring 60 and the idler shaft 46 rotate at the same speed. The shift ring 60 includes at least one spline portion that can engage with the spline portion of any one of the idler gears 56, 58. In addition, the shift ring 60 defines a groove 62 configured to engage with the shift fork.

[0087] The shift fork is coupled to the actuator and is movable to select a first reduction ratio and a second reduction ratio. The shift fork engages with the shift ring 60 so that the shift fork can move the shift ring 60 to engage with one of the idler gears 56, 58. In addition, the shift fork can be moved to a neutral position in which neither the idler gears 56, 58 engage with the shift ring. The shift mechanism 50 may also include a synchronizer to assist in shifting. The actuator may be manually or automatically controlled. The actuator may be responsive to a hydraulic, pneumatic, or electronic signal generated by a transmission control module. Alternatively, the actuator may include a mechanical linkage controlled by a vehicle driver.

[0088] The transmission 30 also includes two output gears 64, 66, as shown in Figures 4a, 4b and 48. Each output gear 64, 66 is coupled to the output shaft 48, the first output gear 64 is engaged with the first idler gear 56, and the second output gear 66 is engaged with the second idler gear 58. The output gears 64, 66 are fixed to the output shaft 48 so that the output gears 64, 66 and the output shaft 48 rotate at the same speed. The output shaft 48 is formed to include a hole 49, which is configured to receive the axle shaft 36. The hole 49 can have a spline or a keyway so that the axle shaft 36 and the output shaft 48 rotate together. As described above, the axle shaft 36 is disposed in the axle support 38 and coupled between the hub assembly 32 and the transmission 30.

[0089] The wheel hub assembly 32 is disposed at the end of the axle support 38 opposite the transmission 30, as shown in FIGS. 4a and 4b. The wheel hub assembly 32 includes a wheel hub 68 having a wheel rim 70. The wheel hub 68 is rotatably supported on the axle support 38 by a pair of wheel hub bearings 72. Bolts, nuts and other fasteners known in the art may be used to secure the wheel 22 to the wheel rim 70.

[0090] Each hub assembly 32 also includes a planetary gear assembly 74 that increases torque to drive the wheels 22. The planetary gear assembly 74 includes a sun gear 76, a planet carrier 78, a plurality of planetary gears 80, and a ring gear (ring gear) 82. The ring gear 82 is coupled to the axle support 38. The sun gear 76 is coupled to the end of the axle shaft 36 and is disposed in the ring gear 82. The ring gear 82 is fixed relative to the sun gear 76.

[0091] A plurality of planet gears 80 are rotatably coupled to the planet carrier 78. The planet carrier 78 is arranged adjacent to the ring gear 82, wherein each planet gear 80 is disposed in the ring gear 82. Each planet gear 80 engages both the ring gear 82 and the sun gear 76. When the axle shaft 36 rotates the sun gear 76, the sun gear 76 rotates each planet gear 80, which in turn rotates the planet carrier 78. The planet carrier 78 is coupled to the wheel hub 68 so that the planet carrier 78 and the wheel hub 68 rotate at the same speed.

[0092] Specific reference Figure 4A, in the drive unit 26 shown, the transmission 30 is in the first reduction ratio, and the torque path shows the torque transmission on the drive unit 26. The torque generated by the electric motor 28 rotates the drive gear 42. The drive gear 42 rotates the driven gear 54 coupled to the idler shaft 46. The idler shaft 46 rotates the shift ring 60 engaged with the first idler gear 56. The first idler gear 56 is engaged with the first output gear 64 to transfer the rotation to the output shaft 48 and the axle shaft 36. The rotation of the axle shaft 36 is further transferred to the wheels 22 through the planetary gear assembly 74.

[0093] Reference now Figure 4B , in the drive unit 26 shown, the transmission 30 is in the second reduction ratio, and the torque path shows the torque transmission on the drive unit 26. Torque is generated in the electric motor 28 to rotate the motor shaft 40 and the drive gear 42. The drive gear 42 rotates the driven gear 54 coupled to the idler shaft 46. The idler shaft 46 rotates the shift ring 60 engaged with the second idler gear 58. The second idler gear 58 is engaged with the second output gear 66 to transmit the rotation to the output shaft 48 and the axle shaft 36. The rotation of the axle shaft 36 is further transmitted to the wheels 22 through the planetary gear assembly 74.

[0094] In one embodiment, Fig.55As shown, the axle assembly 10 may include a first motor assembly 100 for driving a first wheel assembly 102 and a second motor assembly 104 for driving a second wheel assembly 106. Each motor assembly 100 and 104 includes a drive unit 26 and an inverter device 108 coupled to the drive unit 26, and a controller 110 for operating the electric inverter device 108 and the drive unit 26. Each inverter device 108 is coupled to one or more batteries 112 to supply power to the inverter electric inverter 108. Each controller 110 is coupled to a VMU unit 114. In one embodiment, the first motor assembly 100 is configured to operate independently of the second motor assembly 104. In addition, each controller 110 is programmed to operate the corresponding motor assembly at a variable speed. For example, in one embodiment, the VMU 114 can be programmed to transmit a signal to each controller 110 so that during operation, the controller 110 of the first motor assembly 100 can operate the drive unit of the first motor assembly 100 at a first rotational speed, while the controller 110 of the second motor assembly 100 can operate the drive unit of the second motor assembly 104 at a second rotational speed different from the first rotational speed of the first motor assembly 100. In addition, during operation, only one motor assembly can be operated to drive the corresponding wheel assembly, while the other motor assembly allows the corresponding wheel assembly to rotate freely. This gives the axle assembly 10 the ability to not drive one of the electric motors when the load requirement is low. This can be achieved by the controller not supplying power to one of the motors, or by mechanically disconnecting the motor. The disconnection can be achieved by a neutral gear as part of the speed change mechanism or by a clutch, etc. In this (disconnected) mode, the axle assembly 10 operates to drive only one wheel on one side of the vehicle. For example, in a tandem axle (dual axle) configuration (four wheels), the axle assembly 10 can be operated to generate power that can alternate between different motors based on demand and load.

[0095] refer to Figure 5-78In the illustrated embodiment, each outer segment 16 includes a gearbox 116 including a gearbox housing 118 and a gearbox cover 120. The bridge segment 14 includes a cradle assembly 122 coupled to each gearbox housing 118. The cradle assembly 122 includes a cradle frame 124, a top cover 126 removably coupled to a top 128 of the cradle frame 124, and a bottom cover 130 removably coupled to a bottom 132 of the cradle frame 124. The cradle frame 124 includes an inner surface 134 that defines a cavity 136 extending through the cradle frame 124. The top cover 126 extends across the top 128 of the cradle frame 124, and the bottom cover 130 extends across the bottom 132 of the cradle frame 124 to close the cavity 136 to form a cradle chamber 138. The carrier cavity 138 is sized and shaped to receive one or more electrical inverter devices 108 positioned within the carrier cavity 138 .

[0096] The cradle frame 124 includes a front member 140, a rear member 142, a first side member 144, and an opposing second side member 146. The first side member 144 and the second side member 146 extend along a longitudinal axis 148 and are spaced apart a distance along a transverse axis 150 that is perpendicular to the longitudinal axis 148. In the illustrated embodiment, the transverse axis 150 is substantially parallel to the axis of rotation 24 of each wheel 22. The front member 140 is coupled between the first side member 144 and the second side member 146 to form a front portion 152 of the cradle frame 124. The rear member 142 is coupled between the first side member 144 and the second side member 146 and is spaced apart a distance along the longitudinal axis 148 from the front member 140 to form a rear portion 154 of the cradle frame 124.

[0097] The first side member 144 and the second side member 146 each include one or more cable entry openings 156 extending therethrough. The cable entry openings 156 are sized and shaped to receive a plurality of cables therethrough, thereby allowing power and communication cables to extend from the electrical inverter device 108 located within the bracket chamber 138 to an area outside of the bracket chamber 138. The power and communication cables may include, but are not limited to, three-phase cables, two DC cables, motor connection cables, and user interface cables.

[0098] A pair of front mounting flanges 158 extend outwardly from opposite ends of the front member 140. Each front mounting flange 158 includes a mounting member 160 and a support arm 162 coupled between the mounting member 160 and the front member 140. The mounting member 160 is spaced outwardly from an outer surface 164 of the corresponding side member 144, 146 a distance measured along the transverse axis 150. The mounting member 160 includes a flat mounting surface 166 configured to engage an outer surface of the corresponding gearbox housing 118. The flat mounting surface 166 is oriented substantially parallel to the outer surface 164 of the corresponding side member 144, 146.

[0099] refer to Fig.23 and 24 In the illustrated embodiment, the front member 140 includes a top surface 168 and a bottom surface 170 and has a height 172 measured along a vertical axis 174 between the top surface 168 and the bottom surface 170. The mounting member 160 includes a bottom surface 176 and a top surface 178 and a planar mounting surface 166 extending between the bottom surface 176 and the top surface 178. The planar mounting surface 166 includes a height 180 measured along the vertical axis 174 between the top surface 178 and the bottom surface 176 of the mounting member 160. The bottom surface 176 of the mounting member 160 is substantially flush with the bottom surface 170 of the front member 140. The top surface 178 of the mounting member 160 is spaced a vertical distance from the top surface 168 of the front member 140 such that the height 180 of the mounting surface 166 is greater than the height 172 of the front member 140. A plurality of fastener openings 173 extend through the planar mounting surface 166 of the mounting member 160. Each fastener opening 173 is sized and shaped to receive a fastener, such as a bolt, to couple the carrier frame 124 to the gearbox housing 118 .

[0100] In addition, the support arm 162 includes an arcuate (arc-shaped) top surface 182 that extends between the top surface 178 of the mounting member 160 and the top surface 168 of the front member 140. The support arm 162 also includes an arcuate outer surface 184 and an arcuate inner surface 186. The arcuate inner surface 186 defines a gap 188 between the mounting member 160 and the side member outer surface 164 of the corresponding side member 144, 146. The gap 188 is sized and shaped to receive a portion of the gearbox housing 118 therein, thereby facilitating coupling the cradle frame 124 to the gearbox housing 118.

[0101] refer to Figure 12-2663-70, in the illustrated embodiment, the front member 140 also includes a suspension arm support assembly 190 extending outwardly from the outer surface of the front member 140. The outer surface of the front member 140 has an arcuate shape that defines a pair of grooves (slots) 192 between opposite ends of the suspension arm support assembly 190 and the outer surface of the front member. Each groove 192 is sized and shaped to receive an end of the suspension control arm 20, and a mounting surface 194 is defined at each end of the suspension support arm assembly 190 to facilitate coupling the suspension control arm 20 to the suspension arm support assembly 190, as shown. Fig.16 The front member outer surface includes a recess 196 positioned relative to each end of the suspension support arm assembly 190. Each recess 196 is sized and shaped to receive an end of a suspension arm 20 so that each suspension arm 20 extends outwardly from the front member 140 at an oblique angle.

[0102] In the illustrated embodiment, a pair of rear mounting flanges 198 extend outwardly from opposite ends of the rear member 142. Each rear mounting flange 198 includes a rear mounting member 200 and a rear support arm 202 coupled between the rear mounting member 200 and the rear member 142. The rear mounting member 200 is spaced outwardly from the corresponding side member outer surface 164 by a distance measured along the transverse axis 150. The rear mounting member 200 also includes a rear planar mounting surface 204 that is configured to engage an outer surface of the corresponding gearbox housing 118 and is oriented substantially parallel to the side member outer surface 164 and the planar mounting surface 166 of the front mounting member 160.

[0103] In the illustrated embodiment, the planar mounting surface 166 and the rear planar mounting surface 204 of the front mounting member 160 on the same side of the carrier frame 124 are oriented in the same plane to facilitate coupling the carrier assembly 122 to the corresponding gearbox housing 118, as shown. Fig.23 and 24 In addition, the rear planar mounting surface 204 has a height 206 measured along the vertical axis 174 that is substantially similar to the height of the corresponding planar mounting surface 166 of the front mounting member 160. In one embodiment, the front mounting member 160 has a length 302 defined along the longitudinal axis 148 (in Figure 63-70 ), and the rear mounting member 200 has a length 304 defined along the longitudinal axis 148 that is longer than the length 302 of the front mounting member 160.

[0104] Each rear mounting member 200 includes a plurality of fastener openings extending through the rear flat mounting surface 204, the fastener openings being sized and shaped to receive fasteners, such as bolts, to couple the carrier frame 124 to the gearbox housing 118. Similar to the front mounting member 160, each rear support arm 202 includes an arcuate top surface extending between a top surface of the rear mounting member 200 and a top surface of the rear member 142. The rear support arm 202 also includes an arcuate outer surface and an arcuate inner surface. The arcuate inner surface of the rear support arm 202 defines a gap 208 between the rear mounting member 200 and the corresponding side member outer surface 164, the gap 208 being sized and shaped to receive a portion of the gearbox housing 118 therein.

[0105] refer to Figure 27-34 In the illustrated embodiment, the top cover 126 and the bottom cover 130 each include a plate 210 including an outer surface 212 and an inner surface 214 extending between a front end wall 216 and a rear end wall 218 along the longitudinal axis 148, and extending between opposite side end walls 220 along the transverse axis 150. Each front end wall 216 has an arcuate shape that matches the arcuate shape of the inner surface of the front member 140. The top cover 126 and the bottom cover 130 each include a plurality of fastening tabs 222 extending outwardly from the side end walls 220 and the rear end wall 218. Each fastening tab 222 includes an opening extending therethrough that is sized and shaped to receive a fastener to facilitate coupling the top cover 126 to the carrier frame 124.

[0106] The top 128 of the cradle frame 124 includes a top groove 224 defined along the perimeter of the cavity 136 and adjacent to the cradle inner surface 134, the top groove 224 being sized and shaped to receive a portion of the outer edge of the top cover 126 so that the outer surface 212 of the top cover 126 is positioned substantially flush with the top surfaces of the front member 140, the rear member 142, and the side members 144, 146 of the cradle frame 124. A plurality of locating grooves 226 are defined along the top surfaces of the rear member 142 and the side members 144, 146. Each locating groove 226 is sized and shaped to receive a corresponding fastening tab 222 therein. The top surfaces of the rear member 142 and the side members 144, 146 include an opening defined within each locating groove 226 for receiving a fastener therein to facilitate coupling the top cover 126 to the cradle frame 124.

[0107] Similarly, the bottom 132 of the cradle frame 124 includes a bottom groove 228 defined along the perimeter of the cavity 136 and adjacent the cradle inner surface 134, the bottom groove 228 being sized and shaped to receive a portion of the outer edge of the bottom cover 130 so that the outer surface 212 of the bottom cover 130 is positioned substantially flush with the bottom surfaces of the front member 140, the rear member 142, and the side members 114, 146 of the cradle frame 124. A plurality of locating grooves 230 are defined along the bottom surfaces of the rear member 142 and the side members 144, 146 for receiving corresponding fastening tabs 222 therein. An opening is defined within each locating groove 230 for receiving a fastener therein to facilitate coupling the bottom cover 130 to the cradle frame 124.

[0108] Top cover 126 also includes a plurality of openings 232 extending through plate 210 that are sized and shaped to receive fasteners therethrough to facilitate mounting of electrical inverter device 108 within bracket cavity 138 .

[0109] refer to Figure 35-47 71-78, in the illustrated embodiment, the gearbox 116 includes a gearbox housing 118 and a gearbox cover 120. The gearbox housing 118 includes a body 234 having an inner surface 236 and an outer surface 238. The inner surface 236 defines a gearbox cavity 240 that is sized and shaped to receive the drive unit 26 therein. The outer surface 238 extends along the transverse axis 150 between a front portion 242 and a rear portion 244, and along the longitudinal axis 148 between a front portion 246 and a rear portion 248.

[0110] The front portion 242 of the gearbox housing 118 includes a first mounting surface 250 positioned adjacent to the front portion 246 and a second mounting surface 252 positioned adjacent to the rear portion 248, as shown in FIG. Fig.37 14. The first mounting surface 250 is substantially flat and mates with the flat mounting surface 166 of the front mounting flange 158. The second mounting surface 252 is substantially flat and mates with the flat mounting surface of the rear mounting flange 204. The first mounting surface 250 and the second mounting surface 252 each include a plurality of fastener openings extending through the gearbox housing 118, which are sized and shaped to receive corresponding fasteners to facilitate coupling the gearbox housing 118 to the carrier frame 124. In the illustrated embodiment, the front mounting flange 158 is adapted to be coupled to the gearbox housing 118 at the first mounting surface 250 adjacent to the front portion 246, and the rear mounting flange 198 is adapted to be coupled to the gearbox housing 118 at the second mounting flange 252 adjacent to the rear portion 248.

[0111] Axle opening 256 extends through rear portion 244 and is sized and shaped to receive axle shaft 36 therethrough and includes a mounting surface 257 having a hole 259, such as Fig.39 The mounting surface 257 is adapted to receive the axle support 38 to be secured by fasteners. A motor opening 258 also extends through the rear side portion 244 and is sized and shaped to receive a portion of the electric motor 28 .

[0112] In the illustrated embodiment, the front portion 246 and the rear portion 248 of the gearbox housing 118 each include an upper support flange 260 and a lower support flange 262 that is spaced a distance from the upper support flange 260 along the vertical axis 174, such as Fig.38 The upper support flange 260 and the lower support flange 262 are configured to couple the gearbox housing 118 to the base 18 extending outwardly from the gearbox housing 118, thereby facilitating coupling the axle assembly 10 to the vehicle. The front portion 246 includes a suspension arm support flange 264 positioned above the upper support flange 260 along the vertical axis 174. The suspension arm support flange 264 is suitable for coupling the suspension arm 20 to the gearbox housing 118 and is oriented so that the suspension control arm 20 extends outwardly from the gearbox housing 118 substantially parallel to the longitudinal axis 148.

[0113] The front portion 242 of the gearbox housing 118 also includes a mounting shoulder 266 extending outwardly from an outer surface of the front portion 242. The mounting shoulder 266 extends around the periphery of the opening and includes a flat front surface 268. A plurality of holes are defined along the front surface 268 for receiving corresponding fasteners therein to facilitate coupling the gearbox cover 120 to the gearbox housing 118.

[0114] The gearbox cover 120 includes a body 270 having an outer surface 272 shaped to substantially match the shape of the mounting shoulder 266. The gearbox cover 120 includes a plurality of openings 274 extending around the perimeter of the body 270, the openings 274 being sized and shaped to receive fasteners therethrough to facilitate coupling the gearbox cover 120 to the gearbox housing 118. The gearbox cover 120 is adapted to be coupled to the gearbox housing 118 to enclose the drive unit within the gearbox cavity 240. The mounting shoulder 266 includes a locating groove 276 defined along the front surface 268. The gearbox cover 120 includes a locating lip extending outwardly from a surface of the gearbox cover 120 and configured to engage with the locating groove 276 to facilitate coupling the gearbox cover 120 to the gearbox housing 118.

[0115] In the illustrated embodiment, the mounting shoulder 266 extends outwardly from the front portion 242 a distance along the transverse axis 150 such that when the gearbox 116 is mounted to the carrier frame 124 , the gearbox cover 120 is positioned within the gap 278 defined between the front mounting flange 158 and the corresponding rear mounting flange 198 .

[0116] In one embodiment, the axle assembly 10 may include a 700 mm channel ultra low chassis (ULF) with 275 / 70r22.5 tires, 2 speeds: -11.1:1; 19.6:1, a rated axle weight of 11,600 kg, and a range of 750,000 miles. The axle assembly 10 may also include a 1,000 mm channel ULF with 445 / 45r22.5 tires, 2 speeds: 11.1:1; 19.6:1, a rated axle weight of 10,500 kg, and a range of 750,000 miles. The axle assembly 10 may also include a 580 mm channel ULF with 305 / 70r22.5 tires, 2 speeds: 11.1:1; 19.6:1, a rated axle weight of 12,600 kg, and a range of 750,000 miles. The axle assembly 10 may also include a 700 mm channel ULF with one speed, 275 / 70r22.5 tires, 1 speed: 15:1, a rated axle weight of 11,600 kg, and a mileage of 750,000 miles. The axle assembly 10 may also include a 1,000 mm channel ULF with one speed, 275 / 70r22.5 tires, 1 speed: 15:1, a rated axle weight of 10,500 kg, and a mileage of 750,000 miles. The axle assembly 10 may also include a 580 mm channel ULF with one speed, 305 / 70r22.5 tires, 1 speed: 15:1, a rated axle weight of 12,600 kg, and a mileage of 750,000 miles.

[0117] refer to Figures 79-83 In another embodiment, the axle assembly 10 utilizes a single electric motor 28 to drive all wheels 22 coupled to the axle assembly 10. The axle assembly 10 includes a first wheel drive unit 300 that allows for coupling of a first wheel assembly 302 and a second wheel drive unit 304 that allows for coupling of a second wheel assembly 306. The first wheel drive unit 300 and the second wheel drive unit 304 may include some or all of the components of the drive unit 26. In the illustrated embodiment, the axle assembly 10 is a dual wheel configuration, wherein each wheel assembly 302, 306 includes a pair of wheels 22 coupled to each end of the axle assembly 10. The wheels 22 define an axis of rotation 24.

[0118] In the illustrated embodiment, the axle assembly 10 includes a portal axle 308 coupled between the first wheel drive unit 300 and the second wheel drive unit 304 for transmitting torque generated by the first wheel drive unit 300 to the second wheel drive unit 304. The portal axle 308 extends along a centerline axis 310 and is offset and spaced a distance 312 from the rotation axis 24 along a vertical axis 314. The portal axle 308 extends through or around the bridge section 14 of the axle housing 12 between the opposing outer sections 16. In the illustrated embodiment, the portal axle 308 is mounted to be rotated by a first reduction (breakaway) case 316 coupled to the first wheel drive unit 300. The portal axle 308 is adapted to engage a second reduction case 318, which is coupled to the second drive unit 304. The first reduction case 316 and the second reduction case 318 can be any suitable configuration with any number of gear reducers. The portal axle 308 includes a shaft that is rotatably supported in or around the bridge section 14 , one end of the shaft being coupled to a first reduction gear box 316 and the other end of the shaft being coupled to a second reduction gear box 318 .

[0119] like Fig.80 As shown, the first wheel drive unit 300 includes an electric motor 28 and a differential 320 coupled to the electric motor 28. In a manner similar or identical to that discussed above with respect to the drive unit 26, a gear reducer is provided between the electric motor 28 and the differential 320. As described above with respect to the drive unit 26, a transmission 330 may also be incorporated between the electric motor 28 and the differential 320. The differential 320 transfers torque from the electric motor 28 of the first wheel drive unit 300 to the wheel hub assembly 32, and is also coupled to the portal axle 308, thereby transferring torque from the electric motor 28 to the wheel hub assembly 32 of the second wheel drive unit 304 through the portal axle 308. In other words, the portal axle 308 transfers torque from the first wheel drive unit 300 to the second wheel drive unit 304. It should be understood that Fig.81 and 83 The differential 320 is shown with certain components removed.

[0120] In one embodiment, Fig.80 and 81 As shown, each of the first speed reduction box 316 and the second speed reduction box 318 has a single speed reducer, which can be a gear reducer or a 1:1 speed reducer. Fig.80 and 81 The embodiment shown in FIG. 3 has no gear reducer on the portal axle 308. In another embodiment, as shown in FIG. Fig.82 and 83As shown, the first reduction box 316 and the second reduction box 318 have different speed reducers, wherein the first reduction box 316 has a single gear speed reducer and the second reduction box 318 has a double gear speed reducer. Each reduction box 316 and 318 can have the same or different gear reduction ratios. Preferably, Fig.82 and 83 In the illustrated embodiment, there is a gear reducer on the portal axle 308. Specifically, the second wheel drive unit 304 preferably includes a gear reducer 322, which is coupled to the second reduction gear case 318 and the hub assembly 32 at the second wheel drive unit 304. Additional details of the reduction gear case and portal axle whose components can be used in the present disclosure are described in U.S. Patent Application 10 / 389,192 (now U.S. Patent 6,964,317), entitled "Drive Assembly for a High Ground Clearance Vehicle" filed on March 14, 2003 by Groves et al., which is incorporated herein by reference in its entirety. The reduction gear case includes an input shaft that drives an output shaft through a chain drive. The chain drive of the reduction gear case includes an input sprocket, an intermediate sprocket assembly, and an output sprocket. A first chain interconnects the input sprocket and the intermediate sprocket assembly, and a second chain interconnects the intermediate sprocket assembly and the output sprocket. Although a chain and sprockets are shown, gears may be used instead to transfer power from the differential 320 to the portal axle 308 .

[0121] like Figures 80-83 As shown, the axle assembly 10 may include a single electric motor, a two-speed configuration, including a portal axle with a length between 700mm and 1000mm, a channel of 1,000mm or 700mm, 445 / 70r22.5 or 275 / 70r22.5 tires, 2-speed: 11.1:1; 22:1, a rated axle weight of 10,500kg to 11,600kg, and a range of 750,000 miles. The axle assembly 10 may include a single electric motor, a single-speed configuration, including a portal axle with a length between 700mm and 1000mm, a channel of 1,000mm or 700mm, 445 / 70r22.5 or 275 / 70r22.5 tires, 1-speed: 15:1, a rated axle weight of 10,500kg to 11,600kg, and a range of 750,000 miles.

[0122] The present invention has been described in an illustrative manner, and it should be understood that the terminology used is intended to be in the nature of words of description rather than limitation. In light of the above teachings, many modifications and variations of the present invention are possible, and the present invention may be practiced in ways other than those specifically described.

Claims

1. A vehicle axle assembly, the vehicle axle assembly comprising: an axle housing including a first gearbox, a second gearbox, and a carrier assembly coupling the first gearbox to the second gearbox, wherein the carrier assembly is formed to include an internal cavity; a first hub assembly adapted to be rotated by the first gearbox and a second hub assembly adapted to be rotated by the second gearbox, the hub assemblies forming a first axis of rotation; The first gearbox includes a first electric motor having an output shaft and a transmission mounted for rotation with the output shaft; the second gearbox comprising a second electric motor having an output shaft and a transmission mounted for rotation with the output shaft; and An inverter assembly is positioned within the interior cavity of the carrier assembly and is coupled to the first electric motor and the second electric motor to provide power to the first electric motor and the second electric motor.

2. The axle assembly according to claim 1, wherein: The bracket assembly is offset relative to the first axis of rotation. 3 . The axle assembly of claim 1 , further comprising a cover member adapted to cover the interior cavity of the carrier assembly.

4. The axle assembly according to claim 1, wherein: The first gearbox includes a first gearbox housing and a gearbox cover removably coupled to the first gearbox housing, and wherein the bracket assembly is adapted to be removably coupled to the first gearbox housing.

5. The axle assembly according to claim 4, wherein: The second gearbox includes a second gearbox housing and a gearbox cover removably coupled to the second gearbox housing, and wherein the bracket assembly is adapted to be removably coupled to the second gearbox housing.

6. The axle assembly of claim 1, wherein: The first gearbox includes a first axle shaft mounted for rotation with a transmission of the first gearbox; and The second gearbox comprises a second axle shaft which is mounted to rotate with the transmission of the second gearbox.

7. The axle assembly of claim 6, wherein: the first hub assembly includes a planetary gear set mounted for rotation with the first axle shaft; and the second hub assembly including a planetary gear set mounted for rotation with the second axle shaft; Each planetary gear set increases torque to drive wheels coupled to the first hub assembly and the second hub assembly.

8. The axle assembly according to claim 7, wherein: The planetary gear set includes: planet gears; a sun gear of the planet gears coupled to the axle shaft; a planet carrier of the planet gears coupled to the wheel hub; and a ring gear of the planet gears coupled to the hub axle support and remaining stationary relative to the planet carrier and the sun gear.

9. An axle housing, the axle housing comprising: a first outer section, a second outer section, and a bridge section extending between the first outer section and the second outer section; The first outer section is formed to include a cavity configured to accommodate a first wheel drive unit; the second outer section being formed to include a cavity configured to accommodate a second wheel drive unit; and The bridge section includes a bracket assembly having an inner surface defining an interior cavity adapted to receive an inverter assembly for providing power to the first and second wheel drive units.

10. The axle housing according to claim 9, wherein: Each of the first wheel drive unit and the second wheel drive unit includes an electric motor, a transmission coupled to the electric motor, and a wheel hub assembly adapted to be rotated by the transmission.

11. The axle housing according to claim 10, wherein: The hub assemblies of the first wheel drive unit and the second wheel drive unit define a first axis of rotation.

12. The axle housing according to claim 11, wherein: The bridging section is offset relative to the first axis of rotation.

13. The axle housing according to claim 9, wherein: The carriage assembly includes a carriage frame formed to include the interior cavity.

14. The axle housing according to claim 13, wherein: The carrier frame includes a front member, a rear member, and a pair of opposing side members extending between the front member and the rear member.

15. The axle housing according to claim 14, wherein: The carrier frame includes a cable entry defined through each of the pair of opposing side members.

16. The axle housing of claim 14, wherein: The bracket suspension arm support assembly extends outwardly from the front member, the suspension arm support assembly being configured to couple with a suspension arm coupled to a vehicle frame.

17. The axle housing of claim 13, wherein: The cradle assembly includes a top cover removably coupled to a top portion of the cradle frame and a bottom cover removably coupled to a bottom portion of the cradle frame to close the interior cavity.

18. The axle housing of claim 9, wherein: The bridge section is adapted to be removably coupled to the first outer section.

19. The axle housing of claim 18, wherein: The bridge section is adapted to be removably coupled to the second outer section.

20. The axle housing of claim 9, wherein: The first outer section, the second outer section and the bridge section are integrally formed.

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